Power failure alarm



p 4, 1951 G. J. cAss POWER FAiLURE ALARM Filed Aug.. 5, 1949 In ventarGeorge J- Cass Attorney:

Patented Sept. 4, 1951 UNITED STATES PATENT OFFICE POWER FAILURE ALARMGeorge J. Cass, Kansas City, Mo. Application August 5, 1949, Serial No.108,722

This invention relates to a power failure alarm designed toautomatically signal when electrical power is restored to a circuit,should a failure occur.

An object of this invention is to advise a person depending upon anelectric alarm clock to reset his slow or stopped clock after powerfailure has caused it to cease running for a time.

A further object of the invention is to provide a selective switchingcircuit which will actuate the alarm only after power failure when thecurrent is restored.

A further object of the invention is to provide simple means to re-setthe power failure alarm.

These, together with various ancillary objects of the invention whichwill later become apparent as the following description proceeds, arerealized by this invention, a preferred embodiment of which has beenillustrated by way of example only in the accompanying drawing, whereinis shown a circuit diagram of the power failure alarm.

The reference numeral l designates an electric plug adapted to beconnected to a power source. Connected to the plug are a pair ofelectrical conductors l2 and I4. The conductor 14 is connected to oneterminal of a solenoid l6 which is connected by means of conductor Hi toa first switch contact 20. A second switch contact 22 is positionedadjacent the first switch contact 20, A switch 24, actuated by thesolenoid l and adapted to contact switch contact 22 when not held bycurrent going through solenoid l5, and to switch contact 20 whenactuated by the solenoid, is inserted between the switch contacts 20 and22.

The conductor I2 is connected to a fixed contact 26 on the case 28 ofthe selective switch assembly generally designated by reference numeral30. Another switch contact 32 is positioned adjacent the fixed contact26. A push button 34 having a yoke conductor 36 mounted therein and madeof an insulating plastic, such as Bakelite, is biased by coil spring 38upwardly. The yoke 35 is mounted below the fixed contacts 26 and 32 andis urged to contact the fixed contacts by the action of the biasingspring 38. The button has a shoulder portion 40 extendin peripherallytherearound. A conductor 42 is connected to fixed contact 32 at one endand is connected to a fixed contact on the case 28 spaced from the firstset of fixed contacts. This fixed contact is designated by referencenumeral 44. Adjacent the fixed contact 44 and mounted on 1 Claim. (Cl.177-311) 2 the base 28 is another fixed contact 46 connected toconductor l8 by means of conductor 48. A push button 50 of plastic,non-conductive material and having a conducting yoke 52 mounted thereinand adapted to contact fixed contacts 44 and 46, and mounted thereover,is upwardly biased by coil spring 54. The button 50 has a substantiallysemi-spherical recess 56, thus forming bearing surface 58 and thesomewhat further extending retaining surface 60. A rolling bearing 62 isinserted in the recess 56 and is adapted to engage the shoulder 40 ofthe push button 34.

A resistor 64 is connected to conductor l4 in order to reduce thevoltage across the alarm, generally designated by reference numeral 66.The alarm comprises a solenoid 6B actuating vibrator switch H! whichvibrates against bell 12 and contact I4. Condenser I6 is used to reducethe sparking of the bell 12 on breaking contact with the vibrator 10.

The operating procedure of this device is as follows: The plug in isinserted into the desired outlet of a source of current. The alarm isthen set by depressing button 50, thereby closing contacts between fixedcontacts 44 and 46 by means of yoke 52. When button 50 is depressed, asis shown by dotted lines in Figure 1, the bearing 62 is encompassed byrecess 56 and is disengaged from the shoulder portion 40. This allowspush button 34 to rise, and allows yoke 36 to bridge fixed contacts 26and 36. The solenoid I6 is then actuated, causing switch 24 to contactswitch contact 20. This will break the contact between the switch 24 andthe fixed contact 22. The button 50 is then released, maintaining acircuit through conductors I2, 42, switch 24, and conductor !4, as canbe easily seen.

On failure of current from this source, the solenoid l6 releases theswitch 24, allowing the switch 24 to contact switch contact 22 and openthe circuit through the solenoid Hi.

When power is restored, a closed circuit consisting of conductor I 2,yoke 36, conductor 42, switch 24, contact 22, solenoid 68, resistor 64,and conductor I4, is then evident, the solenoid 68 causing the vibratingswitch 10 to sound the bell 12. The bell, therefore, aurally designatesthe return of power to the power failure alarm. The bell may be manuallystopped from sounding by depressing button 50, thus re-energizingsolenoid [5, or by depressing button 34, thus breaking the circuit ofthe alarm.

Since numerous embodiments may be utilized falling within the spirit andprinciples of the invention, it is not desired to limit the latter tothe exact construction shown and described, except as required by thescope of the following claim.

Having described the invention, what is claimed as new is:

An alarm device for indicating return of current to a circuit comprisinga pair of conductors connected to a source of current, a relay solenoidhaving one terminal connected to a first of the pair of conductorsandhaving the other terminal connected to a first switch contact, a secondswitch contact adjacent'said first switch contact, a relay-actuatedswitch connected to a switch circuit actuated by said relay solenoidpositioned between said switch contact selectively contacting saidswitch contacts, an alarm circuit terminally connected to said secondswitch contact and said first conductor, said switch circuit comprisinga first switch connected to said relay actuated switch and to the secondof said conductors, means urging said first switch into a closed circuitposition, a second switch terminally connected to said first switchcontact and said relay operated switch, means urging said second switchinto an open circuit position, and locking means carried by said secondswitch locking engaging said first switch holding said first switch inan open circuit position when said second switch is in a circuit openposition.

GEORGE J. CASS.

10 REFERENCES CITED The following references are of record in the fileof this patent:

UNITED STATES PATENTS 15 Number Name Date 1,343,196 Conway June 15, 19202,310,786 Hildebrand Feb. 9, 1943 FOREIGN PATENTS 20 Number Country Date218,464 Germany Feb.'1, 1910

